Instrument with multiple articulation locks

ABSTRACT

An articulating tool includes proximal, central and distal portions, an articulation mechanism, and first and second articulation locks. The articulation mechanism includes a pair of links, the pair comprising a proximal link on the proximal portion of the tool and a distal link on the distal portion of the tool. The first articulation lock has an engaged position and a disengaged position. When in the engaged position, the first articulation lock impedes movement of the proximal link relative to the central portion about a yaw axis, and corresponding relative movement of the distal link. The second articulation lock also has an engaged position and a disengaged position. When in the engaged position, the second articulation lock impedes movement of the proximal link relative to the central portion about a pitch axis, and corresponding relative movement of the distal link.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/542,589, filed Aug. 17, 2009, which claims the benefit of U.S.Provisional Application Nos. 61/089,748 and 61/089,761, both filed onAug. 18, 2008, the full disclosures of which (including all referencesincorporated by reference therein) is are hereby incorporated byreference herein for all purposes.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

FIELD OF THE INVENTION

This invention relates to articulating mechanisms and applicationsthereof, including the remote guidance and manipulation of surgical ordiagnostic tools.

BACKGROUND OF THE INVENTION

Surgical procedures such as endoscopy and laparoscopy typically employinstruments that are steered within or towards a target organ or tissuefrom a position outside the body. Examples of endoscopic proceduresinclude sigmoidoscopy, colonoscopy, esophagogastroduodenoscopy, andbronchoscopy, as well as newer procedures in natural orificetransluminal endoscopic surgery (“NOTES”). Traditionally, the insertiontube of an endoscope is advanced by pushing it forward, and retracted bypulling it back. The tip of the tube may be directed by twisting andgeneral up/down and left/right movements. Oftentimes, this limited rangeof motion makes it difficult to negotiate acute angles (e.g., in therectosigmoid colon), creating patient discomfort and increasing the riskof trauma to surrounding tissues.

Laparoscopy involves the placement of trocar ports according toanatomical landmarks. The number of ports usually varies with theintended procedure and number of instruments required to obtainsatisfactory tissue mobilization and exposure of the operative field.Although there are many benefits of laparoscopic surgery, e.g., lesspostoperative pain, early mobilization, and decreased adhesionformation, it is often difficult to achieve optimal retraction of organsand maneuverability of conventional instruments through laparoscopicports. In some cases, these deficiencies may lead to increased operativetime or imprecise placement of components such as staples and sutures.

Steerable catheters are also well known for both diagnostic andtherapeutic applications. Similar to endoscopes, such catheters includetips that can be directed in generally limited ranges of motion tonavigate a patient's vasculature. There have been many attempts todesign endoscopes and catheters with improved steerability. For example,U.S. Pat. No. 3,557,780 to Sato; U.S. Pat. No. 5,271,381 to Ailinger etal.; U.S. Pat. No. 5,916,146 to Alotta et al.; U.S. Pat. No. 6,270,453to Sakai, and U.S. Pat. No. 7,147,650 to Lee describe endoscopicinstruments with one or more flexible portions that may be bent byactuation of a single set of wires. The wires are actuated from theproximal end of the instrument by rotating pinions (Sato), manipulatingknobs (Ailinger et al.), a steerable arm (Alotta et al.), by a pulleymechanism (Sato), or by manipulation of complementary portions (Lee).U.S. Pat. No. 5,916,147 to Boury et al. discloses a steerable catheterhaving four wires that run within the catheter wall. Each wireterminates at a different part of the catheter. The proximal ends of thewires extend loosely from the catheter so that the physician may pullthem. The physician is able to shape and thereby steer the catheter byselectively placing the wires under tension.

Recently, surgical instruments, including minimally invasive surgicalinstruments, have been developed that are more ergonomic and which havea wider range of motion and more precise control of movement. Theseinstruments may include mechanisms that articulate using a series oflinks coupled with one or more sets of tension bearing members, such ascables. As with conventional instruments used in minimally invasivesurgery, rotation of the shaft and end effector with respect to thehandle is also an important feature of cable and link type instrumentsto aid with dissecting, suturing, retracting, knot tying, etc. With theincreasing complexity associated with surgical procedures that theseinstruments are used to perform, further improvements in the featuresand design of surgical instruments are desirable.

SUMMARY OF THE INVENTION

According to some aspects of the present invention, an articulating toolis provided with an articulation lock. Methods of using such a tool arealso provided. Embodiments of the articulating tool may be appropriatefor single or multiple uses, including medical uses such as diagnosticand surgical uses. Embodiments of the articulating tool include a shafthaving a proximal and a distal end, an articulation mechanism, and anelongated guide located along at least a portion of the shaft, the guidebeing configured to guide the tension bearing members. The articulationmechanism may include a movable proximal element disposed at theproximal end of the shaft, a movable distal element disposed at thedistal end of the shaft, and a plurality of tension bearing membersextending between the proximal and distal elements such that movement ofthe movable proximal element with respect to the shaft causes acorresponding movement of the movable distal element with respect to theshaft.

In some embodiments of the invention, a tool is provided with proximal,central and distal portions, an articulation mechanism, and first andsecond articulation locks. In these embodiments, the central portion ispivotably coupled to the proximal portion and the distal portion ispivotably coupled to the central portion. The articulation mechanism maybe configured to manipulate an angular orientation of the distal portionrelative to the central portion. The articulation mechanism may includea pair of links, the pair comprising a proximal link on the proximalportion of the tool and a distal link on the distal portion of the tool.The articulation mechanism may be adapted such that movement of theproximal link causes corresponding relative movement of the distal link.In these embodiments, the first articulation lock has an engagedposition and a disengaged position. When in the engaged position, thefirst articulation lock impedes movement of the proximal link relativeto the central portion about a yaw axis, and corresponding relativemovement of the distal link. The second articulation lock also has anengaged position and a disengaged position. When in the engagedposition, the second articulation lock impedes movement of the proximallink relative to the central portion about a pitch axis, andcorresponding relative movement of the distal link.

In some of the above embodiments, the tool further includes an actuatorconfigured to move both the first and the second articulation locks intotheir engaged positions at substantially the same time. The actuator mayinclude a lever located atop the proximal portion. In some embodiments,the proximal portion of the tool includes a handle. The handle and theactuator may be adapted to be operated by a single hand.

In some embodiments, a rotation mechanism is provided on the proximalportion of the tool configured to drive rotation of the central portionrelative to the proximal portion when at least one of the articulationlocks is in the engaged position. The first articulation lock mayinclude a section pivotably coupled to the proximal portion and thesecond articulation lock may include a section pivotably coupled to thefirst articulation lock. The second articulation lock may include amember that slidably receives a part of the central portion.

In some embodiments, the tool includes a grasper located on the distalportion and a handle located on the proximal portion. The handle inthese embodiments may be configured to operate the grasper. The tool mayfurther include one or more of the following members located on thedistal portion of the tool: scissors, a cautery element, an ultrasoundelement, laser optics, illumination optics, a light source, and/or amicrophone.

In some embodiments, methods of using the above tools are provided. Someof the methods include the step of moving the first and the secondarticulation locks of the tool into their engaged positions. In someembodiments, the first and the second articulation locks are moved intotheir engaged positions at substantially the same time. In someembodiments, the method further includes the step of articulating thedistal portion of the tool into an off-axis position by moving theproximal portion before moving the articulation locks into their engagedpositions. Some methods include the step of rotating the central portionof the tool about a longitudinal axis after moving the articulationlocks into their engaged positions. Some methods include the step ofmanipulating a handle located on the proximal portion to operate agrasper located on the distal portion of the tool. In some of thesemethods, the central portion of the tool may be rotated about alongitudinal axis after moving the grasper to a closed position andmoving the articulation locks into their engaged positions.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe claims that follow. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings which are briefly described below.

FIG. 1A is an obliquely distal-looking perspective view of an exemplaryarticulating device having a handle and an end effector. FIG. 1B is adetailed view of the circled portion of FIG. 1A, which includes proximallinks and bushings.

FIG. 2 shows the device of FIG. 1 in a proximal-looking view, with thehandle and end effector in an articulated position. FIG. 2B is adetailed view of the circled portion of FIG. 2A, which includes distallinks and bushings.

FIG. 3 is an exploded perspective view of certain proximal components ofthe articulating device of FIGS. 1 and 2.

FIGS. 4-14 show a first exemplary embodiment of an articulation lock.

FIG. 4 is a right side perspective view of a first embodiment of anarticulation lock shown on the proximal end of an articulating tool.

FIG. 5 is a front perspective view of the tool of FIG. 4.

FIG. 6 is a left side perspective view of the tool of FIG. 4.

FIG. 7 is a top view of the tool of FIG. 4.

FIG. 8 is a bottom perspective view of the tool of FIG. 4.

FIG. 9 is an exploded view of the tool of FIG. 4.

FIG. 10 is a bottom perspective view showing the base component of thetool of FIG. 4.

FIG. 11 is a front perspective view showing the rotating clamp componentof the tool of FIG. 4.

FIG. 12 is a side cross-sectional view taken along the centerline of thetool of FIG. 4.

FIG. 13 is a top cross-sectional view of the tool of FIG. 4 taken alongline 13-13 in FIG. 12.

FIG. 14 is an end cross-sectional view of the tool of FIG. 4 taken alongline 14-14 in FIG. 12.

FIG. 15 is a right side perspective view of a second embodiment of anarticulation lock shown on the proximal end of an articulating tool.

FIG. 16 is a right side plan view of the tool of FIG. 15.

FIG. 17 is a bottom perspective view of the tool of FIG. 15.

FIG. 18 is a top view of the tool of FIG. 15.

FIG. 19 is a front view of the tool of FIG. 15.

FIG. 20 is an exploded view of the tool of FIG. 15.

FIG. 21 is a side cross-sectional view taken along the centerline of thetool of FIG. 15.

FIG. 22 is a cross-sectional view of the tool of FIG. 15 taken alongline 22-22 in FIG. 21.

FIG. 23 is a cross-sectional view of the tool of FIG. 15 taken alongline 23-23 in FIG. 21.

FIG. 24 is a perspective view showing an articulating tool having athird embodiment of an articulation lock.

FIG. 25 is a perspective view showing the tool of FIG. 24 in anarticulated and locked position.

FIG. 26 is an enlarged perspective view showing the proximal end of thetool of FIG. 24 in a centered and locked position.

FIG. 27 is an exploded view showing the proximal yoke of the tool ofFIG. 24.

FIG. 28 is a top view showing the tool of FIG. 24.

FIG. 29 is a cross-sectional view of the tool of FIG. 24 taken alongline 29-29 in FIG. 28.

FIG. 30 is an exploded view showing the distal yoke of the tool of FIG.24.

FIG. 31 is an exploded view showing the pin holder and operating leversof the tool of FIG. 24.

FIG. 32 is a broken away side view showing the articulation lock of thetool of FIG. 24 in an unlocked state.

FIG. 33 is a broken away side view showing the articulation lock of thetool of FIG. 24 in a locked state.

FIG. 34 is a top view showing the proximal end of the tool of FIG. 24.

FIG. 35 is a cross-sectional view of the tool of FIG. 24 taken alongline 35-35 in FIG. 34 showing a second articulation lock in an unlockedstate.

FIG. 36 is a cross-sectional view of the tool of FIG. 24 taken alongline 35-35 in FIG. 34 showing a second articulation lock in a lockedstate.

FIG. 37 is a cross-sectional view of the tool of FIG. 24 taken alongline 37-37 in FIG. 34 showing a first articulation lock in an unlockedstate.

FIG. 38 is a cross-sectional view of the tool of FIG. 24 taken alongline 37-37 in FIG. 34 showing a first articulation lock in a lockedstate.

FIG. 39 is a right side view of a fourth embodiment of an articulationlock shown on the proximal end of an articulating tool.

FIG. 40 is a right side perspective view of the tool of FIG. 39.

FIG. 41 is an enlarged left side perspective view of the tool of FIG.39.

FIG. 42 is a top view of the tool of FIG. 39.

FIG. 43 is a front view of the tool of FIG. 39.

FIG. 44 is an exploded view of the tool of FIG. 39.

DETAILED DESCRIPTION OF THE INVENTION

Articulating tools are described in U.S. Pat. No. 7,090,637; US2005/0107667; US 2005/0273084; US 2005/0273085; US 2006/0111209, US2006/0111210, and US 2006/0111615. The articulating mechanisms of thetools described in those publications use multiple pairs of segments orlinks controlled, e.g., by multiple sets of cables, as well as toolsthat have a single pair of links, connected by a single set of cables,such as those described in U.S. Pat. No. 5,916,146. Depending upon thespecific design of the device, the links can be discrete segments (asdescribed, e.g., in U.S. Pat. No. 7,090,637) or discrete portions of aflexible segment (as described, e.g., in US 2005/0273085). Theinstrument may also include steerable or controllable links, e.g., asdescribed in US 2005/0273084, US 2006/0111209 and US 2006/0111210. Thedevices of this invention may include optional end effectors at theirdistal ends and end effector actuators supported by a handle at theirproximal ends. When using such articulating instruments, a user maymanipulate the proximal end of the instrument, thereby moving one ormore distal links of the articulation mechanism. Aspects of the presentinvention may be used in any of these and in other articulatingmechanisms.

FIGS. 1A and 2A show an exemplary articulatable tool 100 with an endeffector 102 at its distal end and an end effector actuator 104 within ahandle 106 at its proximal end: FIG. 1A shows the tool in a neutral ornon-articulated configuration, while FIG. 2A shows the tool in anarticulated position or configuration. FIG. 1B shows detail (encircledin FIG. 1A) of the proximal links of the tool. FIG. 2B shows detail(encircled in FIG. 2A) of the distal links of the tool. Instrument 100may be used, e.g., in a laparoscopic procedure requiring grasping orcutting within a patient. Exemplary embodiments of the tool 100 may alsobe useful in endoscopic procedures, particularly when, as in someembodiments, the tool has a flexible shaft. Still other embodiments maybe used for percutaneous procedures, such as a catheter. Still otherembodiments include devices that are directed toward natural orificetransluminal endoscopic surgery (“NOTES”). Embodiments of the inventionmay include a wide variety of tools, some with medical or diagnosticpurposes, and others that are applied to other types of tasks where thearticulational capabilities of the tool provide benefit.

Proximal articulation links 108 and 110 extend distally from handle 106,and distal articulation links 112 and 114 extend proximally from endeffector 102. Proximal link 108 is a spindle and is connected to andmoves with handle 106. Likewise, distal link 112 is connected to andmoves with end effector 102. An elongated shaft 116 is disposed betweenthe proximal links and the distal links; in some embodiments the shaftis rigid, in other embodiments the shaft may be flexible.

A set of tension bearing elements or control cables 118 is attached toproximal link 108, extends through proximal link 110, shaft 116 anddistal link 114 and is attached to distal link 112, as shown in FIGS. 1Aand 1B. A second set of tension bearing element or control cables 120 isattached to proximal link 110, extends through shaft 116 and is attachedto distal link 114. In this embodiment, there are three control cables118 in the first set and three control cables 120 in the second set. Itshould be appreciated, however, that other numbers of control cables maybe used to connect corresponding proximal and distal links. In addition,tension bearing elements other than cables may be used to connectcorresponding links. In some embodiments, the tension members maycomprise cables that are capable of only transmitting tension betweenthe links. In other embodiments, the tension members may compriseNitinol wires, rods or other elements capable of transmitting bothtension and compression. In these latter embodiments, a link may bealternately pushed and pulled by at least one tension member. In someembodiments, one set of control cables, such as cables 120, may beeliminated to provide an instrument with a single pair of connectedlinks. What is meant by the word “connected” is that the cable(s) areattached to or are terminated in a pair of links to allow one link todrive another link. This is distinguished from any intermediate linksthat are not “connected”. In these intermediate links, the cables merelyextend through the links in a slidable fashion, and the cables do notdrive movement of the links.

As shown in FIGS. 1A, 1B, 2A, and 2B, movement of handle 106 andproximal link 108 with respect to proximal link 110 moves end effector102 and distal link 112 in a relative and corresponding manner.Likewise, movement of proximal link 110 with respect to shaft 116 movesdistal link 114 with respect to shaft 116 in a relative andcorresponding manner, also as shown in FIG. 2. This relativearticulation movement provides a way for a user to remotely manipulatethe end effector through movement of the handle. It should be understoodthat the proximal and distal links can be connected by the tensionbearing elements so as to move in the same direction with respect to theshaft (thereby providing a mirror image movement) or in oppositedirections with respect to the shaft, depending on whether the tensionbearing elements connect the corresponding links on the opposite sidesor on the same sides of the links, respectively. In addition, the degreeof relative movement can be determined by the relative diameters of thecables' connections to corresponding links as well as through the useand specific design of bushings or spacer links separating the connectedproximal and distal links. For example, in the embodiment shown in FIGS.1-3, the cables' radial spacing on the proximal links is about threetimes greater than their radial spacing on the distal links. This meansthat a movement of about 5° in a proximal link will cause acorresponding movement of about 15° in a distal link. Further details ofthese links are provided in US2005/0273085, which is hereby incorporatedby this reference.

In the embodiment illustrated in FIG. 1, the end effector 102 is a pairof jaws. Actuation force is transmitted from end effector actuator 104through a transmission that includes a linearly movable rod and arotatable rod actuator (not shown). Other end effectors (surgical,diagnostic, etc.) and end effector actuators may be used with anarticulating tool constructed according to this invention. In someembodiments, the distal links themselves can comprise an end effector,such as, for example, a retractor. The movable rod may comprise anyflexible material; in some embodiments Nitinol offers particularadvantages as it is sufficiently flexible to accommodate articulation,and yet can still carry a compressive load sufficiently, for example, tobe able to push open an end effector, such as a set of jaws. In someembodiments, a series of proximal links, themselves, can comprise a“handle” with no other rigid handle being provided. In other words, theproximal links may be formed into a particular shape which is emulatedby a corresponding series of distal links. More details of suchembodiments are provided in U.S. Pat. No. 7,090,637.

FIG. 3 shows an exploded view of certain proximal components of thearticulating tool. The tension members have been omitted for clarity. Asshown, a double headed bushing 109 is disposed between links 108 and110, and another bushing 111 is disposed between links 110 and aproximal end cap 300. The interaction of bushings 109 and 111 with links108 and 110 and with proximal end cap 300 is described in more detail inU.S. 2005/0273084, U.S. 2006/0111209, and U.S. 2006/0111210. If thetension bearing cables 118 and 120 were shown in FIG. 3 as they are inFIGS. 1 and 2, the proximal ends of the three cables 118 would terminatein or otherwise be “connected” to link 108 within openings 1806 of link108, and the cables would pass through openings 1820 in link 110 andopenings 304 in end cap 300 before entering shaft 116. Likewise, theproximal ends of three cables 120 would terminate in or otherwise be“connected” to link 110 within openings 1822 of link 110 and would passthrough openings 304 in proximal end cap 300 before entering shaft 116.A tapered end cap housing or cover 306 may be rigidly fixed to shaft 116to provide a transition from end cap 300 to shaft 116.

As previously noted, device 100 shown in FIGS. 1-3 includes two pairs oflinks, each interconnected by its own set of tension members.Specifically, one pair is formed by proximal link 108 and distal link112 which are interconnected by tension members 118, and another pair isformed by proximal link 110 and distal link 114 which are interconnectedby tension members 120. In other embodiments, only a single pair oflinks interconnected by a single set of tension members is used. In yetother embodiments, three or more pairs of links may be used, eachinterconnected by a discrete set of tension members. In someembodiments, instead of a set of tension members, only a single tensionmember may be used between a pair of links, such as when the tensionmember is capable of also transmitting compression between the links.

As shown in FIG. 3, proximal links 108 and 110 are separated by bushing109, and proximal link 110 is separated from proximal end cap 300 bybushing 111. Proximal bushings 109 and 110 each have a convex sphericalcomponent or ball located at each of their ends. Mating concave recessesare formed in proximal links 108 and 110 and in proximal end cap 300 forreceiving a portion of the ball ends of the bushings. With thisarrangement, proximal links 108 and 110 pivot relative to one anotherabout two pivot points (i.e. about the centers of the two ball ends ofbushing 109). Similarly, proximal link 110 and end cap 300 pivotrelative to one another about two pivot points (i.e. about the centersof the two ball ends of bushing 111). In other embodiments (not shown),links may pivot relative to one another about a single pivot point. Inthe embodiment shown in FIG. 3, protruding pin features are located onopposite sides of each ball and are pivotably received within matingslots located in the concave recesses. This pin and slot configurationallows torque to be transmitted across the four proximal sphericaljoints. Distal links 112 and 114, and distal end cap 400 are separatedby bushings in a similar arrangement.

Referring to FIGS. 4-14, the proximal portion of an instrumentconstructed according to aspects of the present invention is shown anddescribed. The device of this first exemplary articulation lockingembodiment may have a distal portion (not shown) similar to that shownin FIGS. 1-2 and described above. The proximal portion of the deviceincludes an articulation lock. In an unlocked position, shaft 116 andend effector 102 (both shown in FIGS. 1-2) may be articulated relativeto handle 1 in a manner similar to that previously described. Thearticulation lock may then be moved to a locked position in which theproximal end of shaft 116 is held in a fixed orientation relative tohandle 1. In this locked state, the proximal links of the articulationmechanism are prevented from pivoting. Because the proximal and distallinks are interconnected by tension members such as cables, this in turnprevents pivoting of the distal links and locks end effector 102 in afixed orientation relative to the distal end of shaft 116. However, byrotating knob 7, shaft 116 may be caused to rotate about itslongitudinal axis even when in a locked position, and end effector 102is caused to rotate about its own longitudinal axis while being held ina fixed orientation. This feature allows a surgeon to, for example, lockthe orientation of an end-effector 102 when holding a needle, but rotateend effector 102 about its axis for “throwing a stitch.” The orientationof the end effector 102 may be locked and the end effector rotatedregardless of whether the axis of the end effector 102 is aligned withthe axis of the shaft 116 or is articulated to be at an angle to theshaft.

In the first exemplary embodiment shown in FIGS. 4-14, the instrumentincludes a base 2 rigidly attached to handle 1. Rotating clamp 5 ispivotably connected to base 2 allowing clamp 5 to rotate about a yawaxis, as shown in FIG. 4. Turret cover 4 is slidably connected to clamp5 such that it can rotate in an arc about a pitch axis, as also shown inFIG. 4. End cap housing 306 is affixed to the proximal end of shaft 116(not shown in FIG. 4) and is slidably held within a central aperture ofturret cover 4 such that end cap housing 306 may axially translate androtate. With this arrangement, shaft 116 may be articulated about thepitch and yaw axes with respect to handle 1.

Lock 3 may be moved between an unlocked proximal position (as shown inFIG. 4) and a distal locked position. As lock 3 is moved distally intothe locked position, ramp 3C lifts rotating clamp 5 against the downwardbias of wave spring 6 to engage rotating clamp teeth 5C (best seen inFIG. 11) with axis teeth 2C of body 2 (best seen in FIG. 10), therebylocking rotation of rotating clamp 5 about the yaw axis. Clamp 3 alsoincludes an angled groove 3A. As clamp 3 is moved distally into thelocked position, groove 3A causes the top portions of the sides ofrotating clamp 5 to be squeezed together. The bottom portions of thesides of rotating clamp 5 are held at a fixed distance, but they act asa flexible hinge so that the top portions can be squeezed together. Thismovement engages teeth 5A located on the outer periphery of both sidesof rotating clamp 5 (as best seen in FIGS. 11 and 12) with teeth 4B onboth sides of turret cover 4, thereby preventing rotation of turretcover 4 and shaft 116 about the pitch axis. Thus, when lock 3 is in thelocked distal position, shaft 116 (shown in FIGS. 1 and 2) is lockedfrom articulating with respect to handle 1 but may be rotated by turningknob 7 as previously described. Again, when the orientation of shaft 116is locked with respect to handle 1, the proximal links are locked, whichin turn lock the distal links and end effector from pivoting. When lock3 is returned to the unlocked proximal position, shaft 116 may berotated and/or articulated.

Referring to FIGS. 15-23, the proximal portion of a second articulationlock embodiment is shown and described. As in the first embodiment, thedevice of this second embodiment may have a distal portion (not shown)similar to that shown in FIGS. 1-2 and described above. The proximalportion of the device includes an articulation lock. In an unlockedposition, shaft 116 and end effector 102 (both shown in FIGS. 1-2) maybe articulated relative to handle 1 in a manner similar to thatpreviously described. The articulation lock may then be moved to alocked position in which the proximal end of shaft 116 is held in afixed orientation relative to handle 1. This in turn locks end effector102 in a fixed orientation relative to the distal end of shaft 116. Inthis locked state, the proximal links of the articulation mechanism areprevented from pivoting. Because the proximal and distal links areinterconnected by tension members such as cables, this in turn preventspivoting of the distal links and locks end effector 102 in a fixedorientation relative to the distal end of shaft 116. However, byrotating knob 7, shaft 116 may be caused to rotate about itslongitudinal axis even when in a locked position, and end effector 102is caused to rotate about its own longitudinal axis while being held ina fixed orientation. This feature allows a surgeon to, for example, lockthe orientation of an end-effector 102 when holding a needle, but rotateend effector 102 about its axis for “throwing a stitch.” The orientationof the end effector 102 may be locked and the end effector rotatedregardless of whether the axis of the end effector 102 is aligned withthe axis of the shaft 116 or is articulated to be at an angle to theshaft.

In the second exemplary embodiment shown in FIGS. 15-23, the instrumentincludes a base 54 rigidly attached to handle 1. Base 54 includes alower ring, and pivotably supports an upper ring 56 with a four-barmechanism. The upper ring is aligned on a common yaw axis with the lowerring of base 54 for pivotably receiving a gimbal 50, as shown in FIG.17. Gimbal 50 in turn includes two diametrically opposed bores 51aligned on a pitch axis for pivotably receiving opposing bosses 53 ofyoke 52, as depicted in FIG. 20. Yoke 52 includes an axial bore 55 forslidably and rotatably receiving sleeve 64 located on the proximal endof shaft 116. Proximal end cap 300 mates within end cap housing 62 andboth serve to guide the tension bearing members as they enter theproximal end of shaft 116. Sleeve 64 fits covers end cap housing 62 andis therefore rigidly secured to the proximal end of shaft 116. Sleeve 64provides a smooth, cylindrical outer surface that may slide and rotatewithin axial bore 55 of yoke 52. This arrangement allows shaft 116 topivot about the pitch and yaw axes, as shown in FIG. 17, when gimbal 50and yoke 52 are allowed to freely move. Since there is a close slidingfit between the outer surface of sleeve 64 and axial bore 55 of yoke 52,pivoting movement of shaft 116 relative to handle 1 is prevented whengimbal 50 and yoke 52 are in a locked state, as will be described inmore detail below.

When locking lever 58 is in a raised or distal position as indicated bythe arrow in FIG. 16, upper ring 56 is slightly raised and shaft 116 ispermitted to pivot about the pitch and yaw axes as described above. Whenlocking lever 58 is lowered to a proximal, locked position as shown inFIG. 16, upper ring 56 is biased downwardly toward the lower ring ofbase 54. In this locked position, gimbal 50 is squeezed between upperring 56 and lower ring 54 and prevented from pivoting due to frictionbetween gimbal 50 and the rings. Gimbal 50 includes a living hinge 57around its circumference which traverses the diametrically opposingbores (best seen in FIGS. 20 and 23.) As gimbal 50 is axiallycompressed, its living hinge causes its diametrically opposing bores 51to collapse around the bosses 53 of yoke 52. Friction between the bores51 and the bosses 53 prevents yoke 52 and shaft 116 from pivoting aboutthe pitch axis. Therefore, when locking lever 58 is moved to the lockedposition, shaft 116 is prevented from articulation about either thepitch or the yaw axis, but may still be rotated about its longitudinalaxis by turning knob 7. When locking lever 58 is returned to theunlocked position, shaft 116 may be rotated and/or articulated. As canbe seen in FIG. 16, the four-bar mechanism of locking lever 58 may beprovided with an “over center” configuration to alternately bias thelever in either the locked or the unlocked position. In alternativeembodiments (not shown), a sliding clamp such as lock 3 described in thefirst embodiment above, or other linkages or mechanisms may be used tobias rings 54 and 56 together.

Referring to FIGS. 24-38, a third articulation lock embodiment is shownand described. Device 500 of this third exemplary embodiment has aproximal portion 502 and a distal portion 504 similar to those of thedevice shown in FIGS. 1-2 and described above. The proximal portion 502of the device includes a handle 506 and an articulation lock 508. In anunlocked position, as shown in FIG. 24, shaft 116 and end effector 102may be articulated relative to handle 506 in a manner similar to thatpreviously described, as depicted in FIG. 25. The articulation lock 508may then be moved to a locked position, as shown in FIG. 25 for example,in which the proximal end of shaft 116 is held in a fixed orientationrelative to handle 506. This in turn locks end effector 102 in a fixedorientation relative to the distal end of shaft 116. In this lockedstate, the proximal links of the articulation mechanism are preventedfrom pivoting. Because the proximal and distal links are interconnectedby tension members such as cables, this in turn prevents pivoting of thedistal links and locks end effector 102 in a fixed orientation relativeto the distal end of shaft 116. However, by rotating knob 510, shaft 116may be caused to rotate about its longitudinal axis 509 even when in alocked position, and end effector 102 is caused to rotate about its ownlongitudinal axis 511 while being held in a fixed orientation. Thisfeature allows a surgeon to, for example, lock the orientation of anend-effector 102 when holding a needle, but rotate end effector 102about its axis 511 for “throwing a stitch.” The orientation of the endeffector 102 may be locked and the end effector rotated regardless ofwhether the axis 511 of end effector 102 is aligned with the axis 509 ofshaft 116, as shown in FIG. 24, or is articulated to be at an angle tothe shaft, as shown in FIG. 25.

Starting first with reference to FIGS. 27-29, the construction of thearticulation lock 508 of this third exemplary embodiment will bedescribed. Instrument handle 506 includes on a top portion a distallyextending support arm 512. Support arm 512 can be an integral part ofhandle 506 or be a separate component. The distal end of support arm 512may be provided with a central bore 514, and radially extending gearteeth 516 on its upper surface, as best seen in FIG. 27. Flange bushing518 is received within central bore 514 of arm 512. Yoke bearing race520 passes through a central aperture 522 in proximal yoke 524, andpasses through flange bushing 518. Proximal yoke 524 is retained onsupport arm 512 by an E-clip 526 which engages a circumferential slotaround the lower end of race 520. In this manner, yoke 524 rotates withrespect to arm 512 about a vertical yaw axis 528 as race 520 rotateswithin bushing 518, and the bottom surface of yoke 524 rides on thrustbearing surface 530 of bushing 518.

Referring now to FIG. 30, the assembly of distal yoke 532 with proximalyoke 524 is shown. Proximal yoke 524 is provided with two downwardlydepending arms 534 at its lateral extremes. The lower end of eachproximal yoke arm 534 is provided with a through hole 536. Similarly,distal yoke 532 is provided with two proximally projecting arms 538rigidly coupled to a central sleeve 540. The proximal end (relative tothe entire instrument 500) of each distal yoke arm 538 is provided withan inwardly facing blind hole 542. Distal yoke 532 is sized such thatits arms 538 fit over the arms 534 of proximal yoke 524, allowing holes542 of arms 538 to align with holes 536 of arms 534. Two gear segments544 are each provided with an outwardly facing boss 546. Each boss fitsthrough a pair of aligning holes 542, 536 and is rigidly attached to oneof the distal yoke arms 538 with a pin 548, by a press fit, or othersuitable attachment means. With this arrangement, bosses 546 pivotwithin holes 536 of proximal yoke 524, thereby allowing distal yoke 532to rotate about a pitch axis 550 that passes through holes 536. Asdistal yoke arms 538 rotate on the outside of proximal yoke arms 534,gear segments 544 rotate on the inside of arms 534.

Sleeve 540 of distal yoke 532 is designed to slidably mate with drum 552which is rigidly affixed to the proximal end of instrument shaft 116. Inthis exemplary embodiment, shaft drum 552 may freely rotate withinsleeve 540, and drum 552 may also slide axially relative to sleeve 540.In operation, when instrument handle 506 is articulated with respect toshaft 116, distal yoke sleeve 540 is allowed to follow shaft drum 552because distal yoke 532 is allowed to pivot relative to proximal yoke524 about pitch axis 550, and proximal yoke 524 is allowed to pivotrelative to handle 506 about yaw axis 528, as previously described.However, when articulation lock 508 is moved to a locked position aswill be described below, the pivoting of both yokes 524 and 532 isprevented. This locks distal yoke sleeve 540 from further movementrelative to handle 506, which in turn maintains instrument shaft 116 ina fixed angular orientation relative to handle 506. As previouslydescribed, locking the orientation of shaft 116 relative to handle 506consequently locks the orientation of the proximal link(s) of theinstrument. This in turn locks the orientation of the distal link(s)since they are interconnected with the proximal link(s) by tensionbearing members such as cables. When the distal link(s) are in a lockedorientation, axis 511 of end effector 102 (shown in FIG. 25) isgenerally locked in a fixed orientation relative to handle 506 as well.

Referring to FIG. 31, the assembly of additional locking components willbe described. Pin holder 554 includes two downwardly extending long pins556, which are rigidly attached on opposite sides of pin holder 554. Pinholder also includes two downwardly extending short pins 558 (only oneseen in FIG. 31), which are also rigidly attached on opposite sides ofpin holder 554, inboard from long pins 556. Pin holder 554 is alsoprovided with a central bore for receiving a downwardly extending bossof clevis 560. The boss of clevis 560 includes a groove for receivingsnap ring 562. When assembled, clevis 560 may rotate but not moveaxially relative to pin holder 554.

The horizontal portion of proximal yoke 524 includes two outer holes 564for receiving the long pins 556 and two inner holes 566 for receivingthe short pins 558. When assembled, pin holder 554 rotates along withproximal yoke 524 about the vertical yaw axis 528. Pin holder 554, alongwith pins 556 and 558, may also be moved vertically relative to proximalyoke 524 between an upper unlocked position and a lower locked position,as will be described in more detail below.

Lever 568 is pivotably mounted to support arm 512 of handle 506 by pin570. Lever 568 is also pivotably coupled to clevis 560 by pin 572. Aslever 568 pivots about pin 570, lever 568 drives pin holder 554vertically with clevis 560. Spring 574 is mounted on boss 576 of lever568 to urge lever 568 toward a locked position, as will be described inmore detail below. Locking lever 578 is pivotably mounted to support arm512 of handle 506 by pin 580 to drive lever 568.

Referring to FIGS. 32 and 33, details of the operation of levers 568 and578 are shown. FIG. 32 shows articulation lock mechanism 508 in theunlocked state and FIG. 33 shows it in the locked state. First,instrument 500 is articulated into the desired position by pivotinghandle 506 relative to shaft 116, as shown in FIG. 25 for example.Articulation lock mechanism 508 is then operated by moving locking lever578 between a lower unlocked position (FIG. 32) and an upper lockedposition (FIG. 33). This can be accomplished by the surgeon by using thethumb or the index finger of the hand that is holding handle 506.Alternatively, the surgeon may operate locking lever 578 with theopposite hand. When locking lever 578 is pivoted upwardly, a cam surface582 on locking lever 578 allows spring 574 to urge the proximal end oflever 568 in a proximal direction. This in turn causes lever 568 topivot counter-clockwise about pin 570, driving clevis 560 and pin holder554 downward to the position shown in FIG. 33. In this embodiment, camsurface 582 is shaped such that when locking lever 578 is moved arelatively small distance towards the locked position, spring 574 urgeslever 568 against cam surface 582 and causes locking lever 578 to snapthe rest of the way to the locked position and holds it there.Therefore, in this exemplary embodiment, it takes more force to compressspring 574 in moving locking lever 578 to the lower, unlocked positionthan it does to move locking lever 578 to the upper, locked position. Inalternative embodiments (not shown), the contact point between levers578 and 568 may be modified such that locking lever 578 is pushed upward(i.e. rotated counter clockwise) to unlock. In this way, 578 would be upin the unlocked position and down in the unlocked position. Othermechanisms, buttons or sliders that are well known in the art may beused to actuate pin holder 554 and pins 556 and 558 up and down.

Referring to FIGS. 35 and 36 (both cross sections taken along line 35-35in FIG. 34), details of operation of a second articulation lock portion584 of articulation lock 508 are shown. (The first articulation lockportion will be later described.) FIG. 35 shows second articulation lock584 in an unlocked position and FIG. 36 shows it in a locked position.In FIG. 35 it can be seen that when pin holder 554 is moved to itsraised, unlocked position by operation of locking lever 578, the beveledlower ends of long pins 556 are disengaged from the teeth of gearsegment 554 (only one of each are seen in FIGS. 35 and 36), therebypermitting instrument shaft 116 to pivot with distal yoke 532 aboutpitch axis 550. Conversely, it can been seen in FIG. 36 that when pinholder 554 is moved to its lowered, locked position, the beveled lowerends of long pins 556 are engaged with the teeth of gear segments 554,thereby preventing shaft 116 from pivoting about pitch axis 550. Again,motion of shaft 116 is prevented because gear segments 554 are rigidlyconnected to distal yoke 532, which has a sleeve 540 that constrainspivoting movement of shaft drum 552, shown in FIG. 30.

In alternative embodiments (not shown), locking of the distal yoke canbe accomplished in a variety of other ways. For example, a downwardlyfacing concave gear segment may be placed on the lower end of long pin556 and an upwardly facing beveled pin may be coupled to distal yoke forengaging with the gear segment when it is lowered by long pin 556. Inanother embodiment, the long pin may have a smaller diameter andalternately engage with a series of holes formed in a drum located onpitch axis 550 in place of gear segments 554. In yet another embodiment,a brake pad or compressible elastomer may be attached to the lower endof long pin 556 for engaging with a drum located on pitch axis 550 inplace of gear segments 554. In some of these alternative embodiments,there may be discrete detent or locking positions, while in otherembodiments the availability of various locking positions may be fineror infinitely variable.

Referring to FIGS. 37 and 38 (both cross sections taken along line 37-37in FIG. 34), details of operation of a first articulation lock portion586 of articulation lock 508 are shown. FIG. 37 shows first articulationlock 586 in an unlocked position and FIG. 38 shows it in a lockedposition. In FIG. 37 it can be seen that when pin holder 554 is moved toits raised, unlocked position by operation of locking lever 578, thebeveled lower ends of short pins 558 (only one pin 558 seen in FIGS. 37and 38) are disengaged from the gear teeth 516 formed on the distal endof support arm 512, thereby permitting instrument shaft 116 to pivotwith proximal yoke 524 about yaw axis 528. Conversely, it can been seenin FIG. 38 that when pin holder 554 is moved to its lowered, lockedposition, the beveled lower ends of short pins 558 are engaged with gearteeth 516, thereby preventing shaft 116 from pivoting about yaw axis528. Motion of shaft 116 about yaw axis 528 is prevented because shortpins 558 are slidably coupled to proximal yoke 524, and when short pins558 engage with gear teeth 516 they prevent proximal yoke 524 frommoving relative to handle 506. Proximal yoke 524 in turn supports distalyoke 532, which has sleeve 540 that constrains pivoting movement ofshaft drum 552, shown in FIG. 30.

In alternative embodiments (not shown), locking of the proximal yoke canbe accomplished in a variety of other ways. For example, circular pinsfor alternately engaging in a series of mating holes, or other detentmechanisms may be provided instead of short pins 558 and mating gearteeth 516. Alternatively, clutch plates and/or compressed elastomerssuch as o-rings may instead be used for finer or infinite rotationalposition adjustment.

As described above, first articulation lock 586 prevents pivoting motionof shaft 116 relative to handle 506 about yaw axis 528 when engaged.Similarly, second articulation lock 584 prevents pivoting motion ofshaft 116 relative to handle 506 about a pitch axis 550 when engaged.Again it is noted that shaft 116 and end effector 102 may be rotatedabout their axes (509 and 511, respectively) when the articulation locksare engaged or disengaged. Articulation lock 508 of exemplary instrument500 engages and disengages first articulation lock 586 and secondarticulation lock 584 together and at substantially the same time. Inother embodiments (not shown), a single actuator may also actuate boththe first and second articulation locks, but may do so in a staggeredfashion such that one of the articulation locks is actuated first andthe other articulation lock is actuated second. In some of theseembodiments, the instrument may be locked from pivoting about one axiswhile permitting articulation about a second axis which may or may notbe later locked. In other embodiments, separate actuators may beprovided for engaging the first and second articulation locks.Additionally, lockable axes other than the exemplary pitch and yaw axesdescribed above may be used to lock the pivoting movement of anarticulating instrument.

Referring to FIGS. 39-44, the proximal portion of a fourth exemplaryembodiment is shown and described. In some of these figures, bellows 801and guy wires 809, which both normally span between base 802 and tiedown 804, are omitted for clarity. Bellows 801 are configured to coverthe guy wires 809 by spanning from groove 802C to groove 804B. In somefigures, the left or right half of base 802 is also omitted for clarity.The device of this embodiment may have a distal portion (not shown)similar to that shown in FIGS. 1-2 and described above.

The proximal portion of the device includes an articulation lock. In anunlocked position, shaft 116 and end effector 102 (both shown in FIGS.1-2) may be articulated relative to handle 808 in a manner similar tothat previously described. The articulation lock may then be moved to alocked position in which the proximal end of shaft 116 is held in afixed orientation relative to handle 808. In this locked state, theproximal links of the articulation mechanism are prevented frompivoting. Because the proximal and distal links are interconnected bytension members such as cables, this in turn prevents pivoting of thedistal links and locks end effector 102 in a fixed orientation relativeto the distal end of shaft 116. However, by rotating knob 806, shaft 116may be caused to rotate about its longitudinal axis even when in alocked position, and end effector 102 is caused to rotate about its ownlongitudinal axis while being held in a fixed orientation. This featureallows a surgeon to, for example, lock the orientation of anend-effector 102 when holding a needle, but rotate end effector 102about its axis for “throwing a stitch.” The orientation of the endeffector 102 may be locked and the end effector rotated regardless ofwhether the axis of the end effector 102 is aligned with the axis of theshaft 116 or is articulated to be at an angle to the shaft.

In the fourth exemplary embodiment, guy wires 809 are employed to lockthe shaft of the instrument in a fixed orientation relative to handle808. The instrument includes a base 802 rigidly attached to handle 808.Tie down 804 includes an axial bore for slidably and rotatably receivingcylinder 803. Cylinder 803 is rigidly fixed to shaft 116. In thisparticular embodiment, three separate guy wires 809 are used, but inother embodiments fewer or more guy wires may be used. As best seen inFIG. 39, each of the three guy wires 809 (only one of which is shown forclarity) has one end connected to a wire termination hole 804A in tiedown 804, spans proximally to a guy wire hole 802A located in base 802,passes radially inward through locking hole 805A in locking slider 805,radially across locking slider 805 to another locking hole 805A locatedon the opposite side of locking slider 805, radially outward throughanother guy wire hole 802A in base 802, and distally back to anotherwire termination hole 804A in tie down 804. When knob 806 and lockingslider 805 are moved to a distal position (not shown) relative to handle808 and base 802, guy wires 809 may freely move through holes 802A inbase 802 which align with holes 805 a in locking slider 805, therebyallowing one side of a guy wire 809 to get longer and the other side toget equally shorter. This arrangement allows handle 808 to articulaterelative to the proximal end of shaft 116, consequently causing endeffector 102 to articulate relative to the distal end of shaft 116, aspreviously described. On the other hand, when knob 806 and lockingslider 805 are moved to a proximal position as shown in FIG. 39, holes805A become misaligned with holes 802A and guy wires 809 are pinchedbetween locking slider 805 and base 802. This fixes tie down 804 inwhatever orientation it is in when knob 806 and slider 805 are moved,which locks the proximal end of shaft 116 from further articulationuntil the device is unlocked again.

In alternative embodiments (not shown), a locking member such as lockingslider 805 may be configured to lock the guy wires when the member ismoved distally rather than when moved proximally. In some embodiments,locking slider 805 or other locking member is not coupled to shaftrotation knob 806 and therefore moves distally and proximallyindependent therefrom, such that knob 806 is axially fixed.

While the inventive surgical instruments, methods and devices have beendescribed in some detail by way of illustration, such illustration isfor purposes of clarity of understanding only. It will be readilyapparent to those of ordinary skill and in the art in light of theteachings herein that certain changes and modifications may be madethereto without departing from the spirit and scope of the claims. Forexample, while the tool embodiments described in here have typicallybeen in the context of tools with an articulating mechanism comprisingat least two links, the tension member guide system may be used in aninstrument comprising only a single link, a multiplicity of links, andwith any number of tension members such as cables, or numbers of cablesets operably connecting the links. Further, the tension member guidesystem may be used in tools that are absent various features that may beassociated with some articulatable instruments, such as handles,rotatability features, and dedicated end effectors. Finally, while thecontext of the invention is considered to be surgical or medicaldiagnostic procedures, the instruments described herein may have utilityin other non-medical contexts as well.

What is claimed is:
 1. A tool comprising: an articulation mechanismcomprising a pair of links, the pair comprising a proximal link on aproximal portion of the tool and a distal link on a distal portion ofthe tool, the mechanism adapted such that movement of the proximal linkcauses corresponding relative movement of the distal link; a first jointmechanism positioned between the proximal and distal links and pivotableabout a yaw axis; a second joint mechanism positioned between theproximal and distal links and pivotable about a pitch axis; a firstarticulation lock having an engaged position and a disengaged position,wherein in the engaged position, the first articulation lock impedespivoting movement of the first joint mechanism about the yaw axis byfrictionally engaging both a first and a second locking surfaces; asecond articulation lock having an engaged position and a disengagedposition, wherein in the engaged position, the second articulation lockimpedes pivoting movement of the second joint mechanism about the pitchaxis by frictionally engaging both a third and a fourth lockingsurfaces, wherein the engaged position of the first articulation lock isdifferent from the engaged position of the second articulation lock; anda single actuator configured to move between an unlocked position, inwhich both the first and second articulation locks are moved into thedisengaged positions, and a locked position, in which both the first andsecond articulation locks are moved into the engaged positions.
 2. Thetool of claim 1 wherein at least one of the articulation locks includesa projection extendable into the respective joint mechanism to impedemovement of the respective joint mechanism.
 3. The tool of claim 1wherein at least one of the articulation locks includes a dual armclamping mechanism to impede movement of the respective joint.
 4. Thetool of claim 1 wherein the single actuator includes a pivoting lever.5. The tool of claim 1 wherein the single actuator includes a slidableramp.
 6. The tool of claim 1, further comprising a central portionincluding the first and second joint mechanisms and a rotation mechanismon the proximal portion configured to drive rotation of the centralportion relative to the proximal portion when at least one of thearticulation locks is in the engaged position.
 7. The tool of claim 1,further comprising a grasper located on the distal portion and a handlelocated on the proximal portion, the handle being configured to operatethe grasper.
 8. The tool of claim 1, further comprising a member locatedon the distal portion selected from a group consisting of scissors, acautery element, an ultrasound element, laser optics, illuminationoptics, a light source, and a microphone.
 9. A method of using a tool,the method comprising: providing a tool comprising: an articulationmechanism comprising a pair of links, the pair comprising a proximallink on a proximal portion of the tool and a distal link on a distalportion of the tool, the mechanism adapted such that movement of theproximal link causes corresponding relative movement of the distal link;a first joint mechanism positioned between the proximal and distal linksand pivotable about a yaw axis; a second joint mechanism positionedbetween the proximal and distal links and pivotable about a pitch axis;a first articulation lock having an engaged position and a disengagedposition, wherein in the engaged position, the first articulation lockimpedes pivoting movement of the first joint mechanism about the yawaxis by frictionally engaging both a first and a second locking surface;a second articulation lock having an engaged position and a disengagedposition, wherein in the engaged position, the second articulation lockimpedes pivoting movement of the second joint mechanism about the pitchaxis by frictionally engaging both a third and a fourth locking surface;and a single actuator configured to move between an unlocked position,in which both the first and second articulation locks are moved into thedisengaged positions, and a locked position, in which both the first andsecond articulation locks are moved into the engaged positions; andmoving the first and the second articulation locks of the tool betweenthe engaged and disengaged positions.
 10. The method of claim 9 furthercomprising the step of articulating the distal portion of the tool intoan off-axis position by moving the proximal portion before moving thearticulation locks into their engaged positions.
 11. The method of claim9 wherein the tool further comprises a central portion including thefirst and second joint mechanisms, the method further comprising thestep of rotating the central portion of the tool about a longitudinalaxis alter moving the articulation locks into their engaged positions.12. The method of claim 9, wherein the moving step comprises moving boththe first and the second articulation locks into their engaged positionsat substantially the same time.
 13. The method of claim 9, furthercomprising the step of manipulating a handle located on the proximalportion to operate a grasper located on the distal portion of the tool.14. The method of claim 13 wherein the tool further comprises a centralportion including the first and second joint mechanisms, the methodfurther comprising the step of rotating the central portion of the toolabout a longitudinal axis after moving the grasper to a closed positionand moving the articulation locks into their engaged positions.
 15. Thetool of claim 1 wherein at least one of the articulation locks includesa compressible hinge to impede movement of the respective jointmechanism.
 16. The tool of claim 1, wherein the first and second lockingsurfaces are disposed on a set of interlocking gear teeth.
 17. The toolof claim 1, wherein the first locking surface is an internal surface ofa bore and the second locking surface is a surface of a boss extension.